If you've ever raised chickens, no doubt you've seen how they cock their heads from one side to the other. Perhaps their eyes don't allow the best view straight on; after all, their faces are so pointy, they end in a beak! Or maybe - like me - they have a "good" eye and a "bad" eye (without corrective lenses, my vision is 20/400 in my legally blind left eye). So, perhaps chickens check things out with a far-away eye and a close-up eye, just like me - but unlike me - they must roll their entire head from side to side to size things up. Now I know a chicken has a tiny little head and a tiny little brain perhaps the size of a pea. My brain has to switch from the right lobe (eye) to the left lobe (eye)to "decide" which image to process. Do chicken brains have lobes? Split-pea takes on a whole new meaning.
My two disparate eyes send wildly different images to my brain - one much more in focus than the other, depending upon distance. I can almost feel my brain switching eyes much as one shift gears: pause, shift, go. Most of the time this happens subconsciously, but there are times when this becomes uncomfortable - as when one's focus shifts from an entire room, to friends across the table, to the small print on a menu. Because the lenses in my glasses are so different, the size of the corrected images differs enough so that once again my brain must choose the best (sharpest, clearest, most meaningful) image. I usually just remove my glasses, thus eliminating distance vision - and making the near (left eye view) world of friends and menus the only options available .
I read with my (bad) left eye, too. Even though I am distance blind in that eye, my close focus is superb - vastly better than that of my astigmatic right eye. So whenever I read, or do closeup work on a painting, I'm lenses free. But if I need to walk about or look out of the windows, I must grab my glasses once again.
Sometimes I think my extreme visual orientation is precisely because of my impaired vision. I value that which I can see more than anything, because I know that without corrective lenses, I would be severely handicapped. I don't want to miss out on the world around me, so I look and look and look until I can see clearly...